ABSTRACT
<p><b>OBJECTIVE</b>This research intends to amplify the entire coding region sequences of SLC25A13 mRNA which encodes citrin, and to investigate sequence features of the transcripts for this gene in cultured human amniocytes. This study will provide laboratory evidence for prenatal diagnosis of neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) at mRNA level.</p><p><b>METHODS</b>One amniocyte sample was collected from a pregnant woman who underwent prenatal diagnosis of citrin deficiency and whose fetus has proven a carrier of 851del4 mutation by genomic DNA analysis. Another amniocyte sample, as a control, was from a fetus without family history of citrin deficiency. Total RNA was extracted from cultured amniocytes, cDNA was synthesized, and then nested-PCR was performed to amplify the entire coding region sequences of SLC25A13. The PCR products were cloned and analyzed by sequencing.</p><p><b>RESULTS</b>The entire coding region of SLC25A13 gene was successful amplified from two cultured human amniocytes. The splice variant of SLC25A13, SLCA (normal mRNA), was identified in the two samples. SLCB (CAG insertion between exon 9-10) was identified in the control. SLCC (exon 5-11 skipping), but not transcriptional product from the allele with 851del4 mutation, was identified in the 851del4 mutation carrier.</p><p><b>CONCLUSIONS</b>This study demonstrated that the entire coding region of SLC25A13 cDNA can be successfully amplified from two cultured human amniocytes, and revealed exon 5-11 skipping as a novel SLC25A13 transcript. Normal mRNA predominated in the transcripts in normal control and 851del4 mutation carrier, suggesting that the two fetuses were not at risk for NICCD. These SLC25A13 transcription features provided laboratory evidence for prenatal diagnosis of NICCD.</p>
Subject(s)
Female , Humans , Pregnancy , Amniotic Fluid , Cell Biology , Metabolism , Calcium-Binding Proteins , Cholestasis, Intrahepatic , Diagnosis , Cloning, Molecular , Mitochondrial Membrane Transport Proteins , Genetics , Organic Anion Transporters , Polymerase Chain Reaction , Prenatal Diagnosis , Methods , RNA, Messenger , Sequence Analysis, DNA , Transcription, GeneticABSTRACT
This study reports the preparation and identification of soluble programmed death-1 (PD-1) ligand-1 (sPD-L1) and its antibodies of mouse origin. Immobilized metal ion affinity chromatography was used to perform on-column refolding with simultaneous purification of denatured sPD-L1, and soluble sPD-L1 with purity of 95% was obtained. The purified sPD-L1 was verified by immunoblotting using a commercial goat-anti-human PD-L1 antibody. An ELISA-based assay showed that it also had high binding activity for its cognate receptor PD-1. Furthermore, mouse anti-sPD-L1 antiserum of high titer was raised using the purified sPD-L1 as an immunogen, and the specific IgG antibodies were purified using sPD-L1-HiTrap affinity chromatography. In addition, a sensitive sandwich ELISA was established using the purified IgG antibodies together with the commercial goat antibodies. In conclusion, the preparation of soluble sPD-Ll and its antibodies provide the basis for detection of the potential anti-PD-L1 antibodies and soluble PD-L1 in humans as well as for further investigation of its in vivo bioactivities and characterization of its potential receptors.
Subject(s)
Animals , Female , Humans , Mice , Antibodies , Allergy and Immunology , Antigens, CD , Genetics , Allergy and Immunology , Metabolism , B7-H1 Antigen , Chromatography, Affinity , Electrophoresis, Polyacrylamide Gel , Enzyme-Linked Immunosorbent Assay , Escherichia coli , Genetics , Immune Sera , Allergy and Immunology , Immunoblotting , Mice, Inbred C57BL , Recombinant Proteins , Allergy and Immunology , Metabolism , SolubilityABSTRACT
HLA-A* 2402 is one of the most frequently encountered HLA-A alleles in East Asian populations. In order to study the CD8+ T cell responses in Chinese populations, we have described the generation and functional test of HLA-A* 2402 tetramer loaded with HCMV pp65(341-349) peptide (QYDPVAALF, QYD). The cDNA of HLA-A* 2402 heavy chain was cloned by RT-PCR from one of the donors. DNA fragment encoding the ectodomain of HLA-A* 2402 heavy chain fused at its carboxyl-terminal a BirA substrate peptide (BSP) was amplified by PCR with the cloned heavy chain cDNA as a template. The wild-type gene of HLA-A* 2402-BSP was not expressed in Escherichia coli (E. coli), while mutant HLA-A* 2402-BSP gene with optimized codons was overexpressed as inclusion bodies in E. coli. Furthermore, the soluble HLA-A* 2402-QYD monomers were generated by in vitro refolding of washed inclusion bodies in the presence of beta2-microglobulin and QYD peptide. The tetramer was subsequently formed by mixing HLA-A* 2402-QYD monomers with streptavidin-PE at a molar ratio of 4:1. Flow cytometry analysis indicated that this tetramer possessed binding activity with specific CTL from HLA-A24+ donors and the frequencies of tetramer-binding CTL were 0.09% - 0.37% within total CD8+ T cells. This tetrameric agent provides a powerful tool to explore the secrets of CTL responses against HCMV antigens in HLA-A* 2402 individuals.
Subject(s)
Humans , Amino Acid Sequence , CD8-Positive T-Lymphocytes , Cell Biology , Metabolism , Carbon-Nitrogen Ligases , Metabolism , Electrophoresis, Polyacrylamide Gel , Escherichia coli , Genetics , Escherichia coli Proteins , Metabolism , Flow Cytometry , Gene Expression , HLA-A Antigens , Chemistry , Genetics , Metabolism , HLA-A24 Antigen , Oligopeptides , Genetics , Metabolism , Phosphoproteins , Chemistry , Genetics , Metabolism , Protein Multimerization , Recombinant Fusion Proteins , Chemistry , Genetics , Metabolism , Repressor Proteins , Metabolism , Substrate Specificity , T-Lymphocytes, Cytotoxic , Cell Biology , Metabolism , Viral Matrix Proteins , Chemistry , Genetics , MetabolismABSTRACT
Objective:To optimize the renaturation procedure of denatured LexA,prepare the repressor LexA from Pseudomonas aeruginosa(PA),which have the satisfactory biologic activity.Methods:The LexA was renatured by the GSH/GSSG dilution method,and the renatured protein were purified by Ni2+ chelate affinity chromatography and gel filtration chromatography,following desalination by Sephadex G25 gel column.The renaturation result were detected by the native polyacrylamide gel electrophoresis and RPHPLC.The immunological activity of all LexA proteins,including the denatured,renatured protein and the renatured protein that was treated with the DTT,were determined by Western blot.Results:The renatured LexA appears both monomer and multimer,which is confirmed by the native polyacrylamide gel electrophoresis analysis and RPHPLC.Gel retardation experiments shows that the renatured LexA have satisfactory biologic activity.